2018 has been a momentous year for Asana, as the company already raised a $75 million Series D in January and says it's revenue is growing 90% year over year.

With the latest funding round, Asana plans to continue its international growth (first, by opening an office next week in Australia) and increase its number of employees from 400 to 600 by the end of 2019.

On Thursday, Asana announced that it had raised a $50 million Series E funding round, putting the company at a $1.5 billion valuation. The funding round was led by Generation Investment Management with participation from others like Benchmark Capital and Founders Fund. In total, Asana has raised over $2o0 million to date.

"It's really nice to cross over that concrete mark," Asana CEO Dustin Moskovitz told Business Insider, referring to reaching the so-called unicorn status of companies valued at more than $1 billion. "But ultimately it's just a milestone on the way to something much bigger. The market opportunity in front of us is gigantic. We're still just getting started."

2018 has been a momentous year for the work management software company, which its COO Chris Farinacci says, "eliminates work about work."

Earlier this year, Asana raised a $75 million Series D and in early November, announced it had reached 50,000 paying organizations - alongside its over 1 million companies using the product for free. Asana's also said its recurring revenue has increased for seven consecutive quarters, growing at a pace of 90% year-over-year.

"Now it's going mainstream"

"The biggest driver [of growth] is this need for this category," Farinacci says of Asana's product, a cloud-based software service that lets workers collaborate on projects and assign tasks.

"On top of all this collaboration software out there and communication software, there's a need for clarity for teams. We started with selling to the disrupters - the Uber's and Airbnb's and such. But now it's going mainstream and going global."

With its latest injection of funding, Asana plans to expand its international reach. Next week, the company will open an office in Australia and in the first half of 2019, an office in Japan.

The product is already being used in 195 countries and available in 6 languages, and the company says 50% of new revenue is coming from outside the US.

Moskovitz also tells us that the company will grow the number of "Asanas." Today, the San Francisco-based company has around 400 employees, but by the end of 2019, Moskovitz says the goal is to have 600.

After a decade, Moskovitz is as excited as ever

For the one-time Facebook co-founder, Moskovitz seems enthusiastic about the future of his decade-old company.

"Honestly, it's more exciting than ever because the business is taking off. The category is taking off. One way to look at our growth is that we've added more value to the world over the last 15 months than we have in the entire history of the company before that," he explains.

As for what keeps Moskovitz at the company he created immediately after leaving Facebook in 2008, he tells us: "I think this is a really important point of leverage in the world. No matter what type of problem you think about - whether it's health care, education, climate change, any number of non-profits - any of those missions ultimately have a team of people behind it. And those teams need to collaborate well. And that means they need great software like Asana."